‘Google Earth’ Views of Bladder Possible

Photonics.comMay 2011
SEATTLE, May 19, 2011 — A more automated approach to imaging bladders in cancer patients could be cheaper, more comfortable and more convenient than current practices for doctors and patients alike. The new system — designed at the University of Washington — would use the school’s ultrathin laser endoscope with software that stitches together images from the scope’s path to create a full, 3-D panorama of the bladder interior.

Bladder cancer is the fourth most common cancer in men and one of the most expensive cancers to treat from diagnosis to death. After initial diagnosis and surgery, current practice requires patients to return to the urologist at least yearly for a costly, time-consuming and uncomfortable bladder scan. Tumors recur in more than half of patients.

An endoscopic system created at the University of Washington provides a 3-D look at diseased bladders. In this illustration, the green ball represents the bladder. The endoscope follows a spiraling path, shown with arrows, to image the whole interior. Software checks that the scope’s path has covered the entire surface of the bladder. (Images: University of Washington)
“This is trying to bring endoscopy to a more digital, modern age,” said Eric Seibel, a research associate professor of mechanical engineering. “In the current model, a very highly trained person has to do all the manual controls. There’s no electronic record, no longitudinal studies, no remote diagnosis, and you can’t send records anywhere.”

Currently, urologists conduct bladder exams using an endoscope that is manipulated around the bladder during the roughly five-minute scan. Because a specialist is required, some patients must travel long distances for appointments.

A 3-D digital reconstruction illustrates the inside of a stained pig’s bladder. A urologist would inspect this 3-D image looking for signs of tumor growth.
Unlike ultrasound, x-ray and CT scans, endoscopies are performed by medical doctors only. Often no records exist beyond the doctor’s notes. Software in the new system checks that no part of the organ is missed, so a nurse or technician could administer the procedure — especially using a small scope that doesn’t require anesthesia.

“There’s a potential with this technology to semiautomate or fully automate the examination,” said Michael Porter, an assistant professor of urology. “It’s a few years down the road, at least, but the potential is there.”

The software’s user interface projects the reconstructed organ onto a spherical ball or flat map. The resulting mosaic matches the images to a single pixel of accuracy. Ultimately, the digital display would incorporate all the original frames, so a doctor could zoom in on an area of interest and observe from all angles at the highest resolution.

“Essentially, I want to give urologists a ‘Google Earth’ view of the bladder,” said Timothy Soper, a research scientist in mechanical engineering. “As you move the mouse over the 3-D surface, it would show the individual frame showing exactly where that image came from. So you could have the forest and the trees.”